Cosette Pharmaceuticals has announced a definitive agreement to acquire Australian-based Mayne Pharma Group Limited for approximately USD 430 million, creating a major player in the women’s health and dermatology sectors. The all-cash transaction values Mayne Pharma at AUD $7.40 per share and is expected to close in the second quarter of 2025.
The acquisition will significantly expand Cosette’s women’s health portfolio and commercial capabilities, adding multiple patent-protected products to its lineup. Upon completion, the combined company will have 12 patent-protected products focused on women’s health and dermatology, including established brands such as VYLEESI, INTRAROSA, NEXTSTELLIS, ANNOVERA, BIJUVA, IMVEXXY and RHOFADE.
“This acquisition marks a transformational step for Cosette, adding patented, high-growth products to solidify our leadership in women’s health in the U.S. and expanding our reach globally,” said Apurva Saraf, President and CEO of Cosette Pharma. “By combining Cosette’s strong portfolio with Mayne Pharma’s proven commercial expertise, the combined company will be well positioned to further invest in innovation, portfolio expansion and better serve our patients. We look forward to a timely closing and welcoming Mayne Pharma to the Cosette family.”
The combined entity will leverage the strengths of both companies. Cosette brings its 350+ team members and women’s health product portfolio, while Mayne Pharma contributes a 480+ strong team with established sales and marketing capabilities in specialty areas. The resulting organization will operate two FDA-approved manufacturing facilities – one in Lincolnton, North Carolina and another in Salisbury, South Australia – to serve patients globally.
“Joining the Cosette team amplifies our shared mission to improve lives through innovative and accessible Women’s health and dermatology medicines,” said Shawn Patrick O’Brien, CEO, Mayne Pharma. “This transaction represents a unique opportunity for our employees, customers, and patients. Together, we will extend the reach of important therapies, drive innovation, and improve patient access.”
The acquisition has been approved by the boards of directors of both companies, with Mayne Pharma’s board unanimously recommending that shareholders vote in favor of the transaction. Upon completion, the combined company will be privately held. Cosette is backed by Avista Healthcare Partners and funds managed by Hamilton Lane, while Mayne Pharma is currently listed on the Australian Securities Exchange (ASX: MYX).
The transaction remains subject to customary closing conditions, including regulatory and shareholder approvals. Cosette is being advised by Santander US Capital Markets LLC and UBS Investment Bank as financial advisers, while Mayne Pharma is being advised by Jefferies Australia.
